Hydraulic operator



0cm, 1941. V E J, HULL- 2,258,493

HYDRAULId orlwrog z QS- L ATTORNEY.'

Oct. 7, 1941.' E, J, HULL 2,258,493

HYDRAULIC OPERATOR Filed Jan. 25, 1940 4 sheets-sheet 5 V/z/ Y Uhr w55 7,V E. J. mRAULIc'oPl-:RATOR 4 Sheets-Sheet 4f Filed aan. 25, 1940 l 1N VENTOR. faim/72 Ilia/A ATTORNEY.

Patented Oct. 7, 1941 HYDRAULIC OPERATOR Edwin' J. Hull, Cleveland, Ohio, assignor to Trabon Engineering Corporation, Cleveland, Ohio, a corporation of Ohio Application January 25, 1,940, Serial No. 315,563

My invention pertains to animproved hydraulic operator and to improved snap action valve operating mechanism.

It is an object of my invention to provide a hydraulic operator having an improved simplified valve construction such that any desired number of sets of ports may be conveniently, simply and economically provided, each having any desired number Iof port holes for ample flow capacity arranged in accurate cooperative relation to a simple balanced valve and conductively related to suitable fluid flow passages in an enclosing housing.

Another object of my invention is 'to provide such a hydraulically operated device in which the movable valve is balanced both radially and longitudinally to provide for freedom of operation and reduction of wear.

Fig. is an enlarged cross-sectional or detail View, taken on line 54-5 of Fig. 4. to show the arrangement of the spring clip, in the slack motion connector-for coupling the valve with the spring floating spool on the valve rod;

Fig. 6 l's a centralsectional detail view taken on line 6-8 of Fig. 5, showing the slack motion A further object of my invention is to provide a hydraulic control valve comprising an improved valve actuating mechanism.

A further object of my invention is to provide, in a hydraulic operator, lost motion between the valve and its actuator whereby the valve will not shift until after its snap acting mechanism has passed dead center.

Further objects and advantages are within the scope of my invention, such as relate to the arrangement, operation and function of the related elements of the structures, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification in conjunction with thedrawings disclosing a specific embodiment of my invention, similar reference characters being applied to similar elements throughout; and in which:

Fig. 1 comprises a side elevational view of my .improved hydraulic operator shown in conjunction with a barrel pump, partially broken away and sectioned to show the `internal elements thereof, the pump and hydraulic pistons being shown in the uppermost position, and the barrel being shown in dotted lines; n

Fig. 2 is a similar View showing the pistons of the pump and the hydraulic operator inthe lowermost positions;

Fig. 3.is a top planview of the hydraulic operator; v

Fig. 4 is an enlarged central sectional view of the hydraulic valve and housing portion of-the unit, which is shown in elevation in Figs. 1 and 2, the hydraulic piston and valve being shown in the uppermost position;

connection between the valve and the ca m spool;

Fig. 7 ls a cross-sectional view on line 1--1 of Fig. 4 showing the snap acting cam operator for the valve;

Fig. 8 is a central sectional view taken II-II of Fig. 3 and shown on the vsame scale. the lower portion of the unit being shown partially in elevation and partially broken away (showing a section through the valve mechanism substantially at right angles to the section view shown in Fig. 4)

Fig. 9 is an enlarged cross-sectional view taken on line 9-9 of Fig. 8;

Fig. 10 is an enlarged cross, sectional view on line IIl-Ill of Fig. 8;

Fig. 11 is an enlarged cross sectional View on line Il-II of Fig. 8;

Fig'. 12 is a cross-sectional view taken on line I2-I2 of Fig. 13; and

Fig. 13 is `a central sectional view of the hydraulic mechanism similar to Fig. 4, except that in this view the mechanism is shown in the lowermost position.

Referring more particularly to Figs.,1, 2 and 3 of the drawings, by improved hydraulic operator is shown in conjunction with a barrel pump, comprising a compact eilicient assembly of several parts `or elements consisting 4of a main or lower pump cylinder` I made of ytubing selected of a suitable diameter and length for insertion through the bung of any grease or oil barrel or drum 3 (shown in dotted lines) which it is desirable to evacuate. The pump cylinder I may be constructed in various lengths for use in dilerent sizes of grease drums, as this tube must be long enough to come within approximately one inch of the bottom of the grease drum. The

lower end of the cylinder tube opens from the drum through a check valve unit 5 of any suitable construction. An inner or upper pump cyl inder 'I is concentrically supported in the upper end of the main pump cylinder providing an annular liquid discharging passage 8 therebetween. Where the hydraulic operator is otherwise used, this cylinder 'I coacts with a coupler member I3 that unites the hydraulic operating rod to the piston shaft in forming a stung box. A piston assembly 9 slides snugly in the main pump cylon line inder I and is connected operatively through a piston Irod II to a smaller piston I3 which slides snugly in the smaller cylinder. From the other side of the smaller pump piston I3 a tubular piston rod |5 extends upwardly for connection with a hydraulic operator by which the two pump pistons are simultaneously actuated in the respective pump cylinders. Underscored reference characters designate a unit or assembly broadly,y ratlierthan specific elements thereof. The piston rod I I acts as the hydraulic operating rod for performing useful work where the hydraulic operator is not used for operating a pump.

The hydraulic operator comprises a hydraulic piston assembly I9 secured on the upper end of the tubular piston rod I and operatively slidable in a hydraulic cylinder 2|. On the upper end of the cylinder 2| is mounted a valve housing 23, enclosing an improved valve and valve actuating mechanism to be subsequently described. A valve actuating rod 25 extending down from the valve mechanism through the piston I9 into the hollow piston rod I5, has a collar 21 firmly secured on the lower end of the rod in any suitable manner, as by riveting. Resting loosely in the bottom of the hollow piston rod I5 is a spacer 29 which engages the lower end of the valve rod and pushes it up to actuate the valve as the hydraulic piston rod approaches the upper end of each stroke. iVhen the hydraulic piston I9 moves down, approaching the lower end of each stroke, the collar 21 is engaged by a portion of said piston (hereafter to ,be described) to draw the valve rod 25 down, and the hydraulic piston continues to reciprocate to actuate the pump pistons as long as fluid under pressure is supplied thereto, in a manner to be subsequently more fully described.

Fig. 1 also shows the construction of a connector casing 3|, which may be made of any suitable cast metal, and which, in this instance, serves to connect together, in suitably spaced relation, the adjacent ends of the pump cyll inders I and 1 and the hydraulic cylinder 2|.

Where the rod II is to be used as a power operator, the cylinder I and the other pump parts are omitted, the connector casing 3| then merely connecting cylinders 1 and 2|. For this purpose the 4connector casing 3| is provided. It is preferably a hollow casting of a generally tubular conformation being internally threaded in the lower end for receiving the -upper end of the large pump cylinder tube I which has a corresponding external thread. The pump cylinder I is provided with an annular collar 33, which is secured in any suitable manner, as by welding 35, and the top side of the collar is of a substantially reduced diameter for fitting into an annular/recess or enlarged counterbore 31 in the lower.,.end` of the aperture in the casing 3|. Suitable packing may also be provided.

As here illustrated and shown, a discharge port 39, opening from the side of the casing 3|, is provided with an enlarged, internally threaded, counterbore 4I in the open outer end for connection with any suitable pipe or hose through which the pumped liquid is to be delivered. The discharge port 39 opens from an enlarged annular passage 40 in the casing which collects liquid lfrom the upper and 0f the annular space 8 between the two pump cylinders I and 1, and leads the liquid to the outlet port 39 with a minimum loss of pressure due to friction. Y

Above the discharge port 39, the casing '3| is internally threaded for receiving and firmly supporting an annular collar 43 in which the upper end of the smaller pump cylinder`1 is attached in any suitable manner. Suitable wrench receiving depressions 45 are provided in the upper side of the cylinder supporting collar. The cylinder 1 supported at the upper end in the collar 43 serves also to close the upper end of passage 8 so that liquid lifted or forced therein by the movements of either pump piston is forced out of the pump casing through the discharge port 39. The upper end of the casing 3| is provided with an enlarged counterbore for receiving and seating the lower end of the hydraulic cylinder 2| in aligned relation with the pump cylinders.

Fig. 1 also shows the construction of a suitable check valve unit 5 for the lower end of the pump cylinder I although various types of suitable check valves are available. Such check valve may comprise a valve body, which may be a casting 41 of a generally circular cross-section and of a suitable reduced diameter for fitting into the lower end of thepump cylinder having a flange 49 of enlarged diameter forming a shoulder for abutting the lower edge of the pump cylinder. A passage 5| opens through the valve casting 41 into the pump cylinder. For closmg the passage 5| against reverse or downward ow, a valve disk 53 is disposed thereabove on the upper end of a guide stem 55 which slides in the valve casting. To provide a good seating contact, a raised bead or flange 51 of generally annular conformation may be provided on the upper side of the valve casting 41 around the port; 5I for engaging the valve disk. A screen 59 is preferably secured in the lower opening of the valve passage 5I to prevent the entrance of dirt and foreign matter. -Spacing lugs 6I are preferably provided projecting down from the valve casting 41 to support it spaced above the bottom of the drum 3 so that the grease or other liquid may freely enter the pump. As the lower pump piston 9 is lifted, the check valve 53 is lifted to the uppermost position ind1cated by dotted lines, in Fig. 1, and grease from the drum flows through the check valve assage 5| into the space in the lower end of e arger pum .c linder I piston. D y evacuated by the As the piston 9 begins to descend, the check valve 53 closes, as seen in Fig. 2, trapping the grease which then passes through a check valve iin theiptistiolrli 9 lslg that the grease previously rawn no ecy' derlisthena instead of below it. beve the plston The trapped liquid under the piston 9 can not escape from the bottom of the pump cylinder I because the check valve 53 closes, so the grease under the piston 9 passes through the piston into the space above the piston. When the piston 9 reverses and moves up, the usual check valve therein closes and the piston lifts the quantity of grease above it, forcing it through annular passage 8 between the two pump cylinders and out of the discharge port 39. At the same time a fresh charge of grease is being drawn into the bottom of the pump cylinder below the piston 9. E ach downward stroke of the pump pistons also discharges a quantity of grease from the discharge port 39 because, as the upper piston I3 moves down, it displaces a quantity of grease from the cylinder 1. Since the displaced grease can not go down and escape from the bottom of the pump cylinder I because of the closing of the check valve as previously explained, since the grease below piston 9 passes therethrough to a position above piston 9, a volume of grease equal to that displaced from cylinder I is forced up through the annular passage 8, between the two pump cylinders I and 1, and out through the discharge port 39.

In this manner a double action is obtained as the pump is operated to deliver grease or other liquid from the drum 3. Both pistons 9 and I3 are preferably arranged to displace, i. e., discharge a like volume of grease in order to make the double action of the pump as uniform as pos--D sible. To accomplish this, it is desirable to have the displacement capacity of cylinder 1 as nearly equal to half that of the lower cylinder as possible. When this relation is established, the volume of grease lifted by the upward stroke of the large piston is divided, half following the smaller piston to lill the space that .would otherwise be evacuated by its upward movement and the other half of the grease being forced out of the discharge port 39. On the downward stroke the smaller ,piston then` displaces and discharges the other half of the volume of grease which was previously lifted. The downward stroke of the lower or larger piston 9 does not cause any discharge of grease because the usual check valve in this piston merely opens and permits the grease to flow through this piston.

Fig. 1 shows the construction of the coupling member |3 which connects rods I5 and and which slides in the inner pump cylinder 'I for displacing grease on the down stroke of the pump, otherwise acting merely as a stuilng box for the hydraulic operator. Any suitable sliding scalable means may be used to couple the rods l5 and together, so long as the fluid under pressure in the cylinder 2| cannot escape through the cylinder 1, or where the device is not to be used as a pump, the stuilng box m-ay be xedly mounted and the rod may comprise an extension of the rod I5 which merely slides through the stuiing box. Referring to Fig. 4 the hydraulic operator comprises a hydraulic piston I9 which reciprocates in the hydraulic cylinder 2| in response to different iiuid pressures applied alternately to opposite sides of the piston by means of an improved valve mechanism, to be subsequently de-4 scribed. A piston suitable for this purpose may comprisea piston member |05 having a central aperture |01 therethrough which is internally threaded for firmly receiving the upper threaded end of the tubular piston rod |5 through which the working forces are transmitted for actuating the pump pistons. A complementary piston member |09 is secured on the upper side of the main piston member |05, as by screws passi'ng thereinto. The complementary piston member maysubstantially close the upper end of the aperture |01 in the main piston member except for a smaller aperture I3 which freely passes the valve rod 25 through to the bottom of the hollow piston rod I5 but engages the collar 21 attached on the lower end of the rod(Fig. 1), when the piston moves down far enough. The hollow piston rod I5 may be turned into the threaded central aperture |01 in the main piston member until the upper end abuts the complementary pis,- ton member, as shown.

A pair of yieldable piston leathers ||5, of usual cup shape are clamped between the two piston members of the hydraulic piston with the cupped edges turned in opposite directions for iitting shown. It is to be understood that the so-called pump Leathers" may be made of any suitable yieldable material, or if desired piston ring types of pistons maybe utilized in the hydraulic oper-` ator and in the pumps.

Fig. .4, also shows the valve mechanism, comprising a valve housing ||9 which fits upon the upper end of the hydraulic cylinder 2| for controlling the application of different fluid pressures alternately to opposite `sides of the hydraulic piston for working the pumps. The valve hous ing may be a casting of any metal selected suitably in accordance with the pressure, temperatures and chemical or corrosive properties of the medium to which it will be exposed, in accordance with the usual practice. The lower end of the valve housing ||9 is provided with circular recess |2| suitably machined to fit snugly on the upper end of the hydraulic cylinder 2|. A compressible gasket |23 of annular shape may be placed on the upper and lower ends of the tubular cylinder 2| for making sealed joints. For drawing the valve housing and the connector u casing 3| firmly togetherclamping upon the op- The valve housing ||9 is provided with a cen- -tral aperture or bore |3| of large diameter which opens from the top of the housing and has a flange or shoulder |33 turned inwardly toward the axis of the bore around the bottom or lower edges thereof. The valve rod 25 projects up axially through the central aperture in the valve housing, the 'upper end extending slightly above the upper end of the housing. The lower end of the main bore I3| is closed by a bottom disk |35 which ts snugly down upon the ilange |33 and 4has a central aperture for slidably passing the valve rod 25 therethrough. The .top side of the bottom disk -is also provided with a packing gland |31 surrounding the valve rod and packed with any suitable yielding packing material |39 for providing a liquid seal therewith. A circular plate |4| suitably apertured to pass the valve rod 25, is placed down on the bottom disk to clamp the packing Iaround the valve rod.

A stationary ported cylinder |43 is disposed in the central aperture |3| supported in concentric spaced relation from the side walls thereof by a plurality of annular spacer rings |45, each having an inner groove |41 and an outer groove |49 'connected together through passages |5| extending radially through the web portion of the ring between the inner and outer groove. Between the spacer rings |45 annular gaskets |53 are inserted, made of any suitable yieldable material which is oil proof and of a size suitable for tting snugly provided with four sets of circumferentlally spaced port holes |55, the different sets being positioned at four different elevations above the lbottom of the central aperture suitable for connection with the four separately enclosed annular spaces in the spacer rings |45. Sliding snugly in the valve port cylinder |43 is a balanced valve |51 of generally cylindrical conformation and having a Wide groove |59 cut circumferentially in the outer surface. The valve groove |59 extends axially on the outer surface of the valve a distance which is greater than the'axial distance between axially spaced different sets of port holes |55 in the ported cylinder, as shown. The valve |51 and the ported cylinder |43 are finished for a snug fit so that alight Working liquid or oil may be used under pressure for actuating the hydraulic operator. A central aperture |6| is provided extending axially through the valve and of a suitable size for passing the valve rod 25 freely therethrough. From the lower end of the valve housing, fluid conducting passages |62 are drilled up axially into the side walls of the valve housing ||9 around the central aperture to provide a conduit from the upper end of the hydraulic cylinder 2|. The upper ends of these passages |62 are connected into the central passage in the housing by drilling passages |63 diametrically from one side of the housing and closing the outer opening by means of a plug |85. Any desired number of such passages may be similarly provided. As shown, the diametral passage |63 is suitably disposed to connect into the annular grooves defined by the top spacer ring |95.

As may be seen from Figs. 4, and 6, the valve |51 is not directly actuated from the valve rod 25, which slides freely therethrough, but is actuated through a slack motion connection comprising a thin neck or sleeve |81 which extends up around the valve rod 25 from the upper end of the valve into a recess |69 in the lower end of a cam spool |1|. An annular groove |13 is provided in the outer surface of the valve neck |61 for receiving in opposite sides the two resilient prongs |15 of a spring clip |11 in a manner, which may be seen more clearly in Figs. 5 and 6, where it may also be seen that the side wall |1| which surrounds the recess |69 in the cam spool is provided with oppositely disposed slots |19 for passing the spring prongs |15 through to engage the valve neck |61. The slots |19in the lower end of the cam spool |1| are axially longer than the axial dimension or Width of the spring prongs |15 passed therethrough, and this amount of slack motion is provided between the valve |51 and the cam spool. When the cam spool |1| is moved down or up sufficiently so that the upper or lower side of the slot |19 engages the` lower or upper edge of the spring clip prongs |15, a positive driving connection is established and the' valve is actuated.

Fig 4 shows that the cam spool |1| is provided with an axial aperture |8| having a reduced portion providing a ange ring |83 at the lower end through which the upper end of the valve rod 25 passes. The inserted portion of the valve rod 25 is of reduced diameter and receives a compression spring |85 concentrically thereon for pushing apart a pair of split retaining rings |81 closed thereon for engaging the spaced shoulders |88 thus provided on the rod. A'n intermediate shoulder |88' on the `reduced portion may under certain conditions positively engage ring |81 to drive positively. The upper end of the aperture [8| is provided with a threaded enlarged counterbore which receives an apertured thimble |89 screwed therein with the upper end of the rod passing through the aperture and having a knob |90 of larger diameter thereon. The retaining rings are thus ,spring pressed apart against the thimble |89 at the upper end of the cam' spool and the ange ring |83 at the lower end of the spool and a movement of the valve rod up or down engages a shoulder on the rod against the lower or upper spring pressed retaining ring respectively.

For restraining the movement of the cam spool |1| until a predetermined actuating force has been applied, I provide a pair of spring pressed ball contactors or camming balls |9| engaging the outer side surfaces thereof at diametrically opposite points as shown in Figs. 4 and '1. To provide suitable camming surfaces to be engaged by the contactor balls |9| on the outer surface of the cam spool, a pair of grooves |93 and |94 are cut 'circumferentially therein at axiallyl spaced positions, as shown. When the cam spool |1| is at the upper position, the contact balls |9| nest snugly in the lower groove |93, and when a predetermined actuating pressure has been applied to draw the spool |1| down, the camming balls suddenly climb over the separating ridge |95 and enter the upper groove |94 causing the cam spool to snap down, engaging the spring prongs |15 on the neck |61 of the valve |51 and throwing the latter suddenly to its lowest extreme position.

The camming balls |9| are each continuously pressed in against the cam spool |1| by a compression spring |96, the inner end of which rests against the ball, the outer end being nested in a pocket |91 in a spring cap |99 screwed into a threaded aperture 20| opening outwardly from the valve housing. A ball guide sleeve 203 is secured against the bottom of the threaded aperture with a reduced portion 205 extending through a smaller aperture into the central bore ||9 and receiving the ball for slidably guiding the movements thereof adjacent the cam spool. A hole 201 is provided in the upper side of the ball guiding sleeve for receiving lubricant kto minimize friction and wear on the cam ball. The outer end of each spring cap |99 is suitably shaped to receive a wrench for removal or adjustment.

The upper end of the central aperture or bore |3| in the valve housing is closed by a dome cover 209 having a laterally extending flange 2|| for abutting the upper surface thereof and a cylindrical flange 2|3 for fitting down into the central aperture in the housing. On top of the spacer rings |45 is a cylindrical sleeve 2 5 which extends up above the camming balls |9| and has apertures 2|1 through which the ball guides 205 are passed.

Fig. 8, which is a vertical view taken through the hydraulic operator at right angles relative to Fig. 4, shows the inlet port 2 9 which is drilled through a boss 22| projecting from the side of the valve housing at a suitable position for conductively connecting with the second groove and the second set of port holes on the central aperture. The inlet port 2 9 is also seen in the crosssectional View shown in Fig. 9. 'Ihe boss 22| is also drilled to provide a passage 223 entering the housing below the inlet port at a position for connecting with the third groove and the third set of port openings in the port cylinder. The outer end of the drilled passage 223 is closed by a plug 225. An intersecting passage 221 is drilled to open down and is arranged to receive one end 3,258,493 of a pipe 229 which extends down to a suitable pipe ntting 23| connecting into a passage 233 in a boss' 235 projecting laterally from the pump connecting casing 3|. A passage 231 is drilled radially into the casing intersecting the lower end of the upward passage 233 and closed by a f plug 239 at the outer end. In this manner a conductive connection is provided from the lower end ofthe hydraulic cylinder 2| by way of passages 231, 233,229, 221 and 223 into the third `V set oi'port holes |55 in the port cylinder |43.

Any desired number o! suchpassages'may be provided-p i Figs. 8 and' 10,y also show, the exhaust port 24| -drilled radially through boss 243 into the valve housing to enter the` lower spacer ring and the Ilower` set of` port holes. 'I'he exhaust also connects up through passages 245'and 241 into the fspace in 'the central aperture |3 in the valve housing above the valve and thespacer rings.

L stroke,`with a quick snappy action toits lower- This latter exhaust, connection is effective leach time 'the valve .|51moves down to its lower position. as shown in Fig.' 13, whenthe working pressure oil that is exhausted from the upper end oi.' the hydraulic cylinder enters the central aperture or bore of the valve housing through the upper set of'port holes oi the ported cylinder andthen ilo'wsl up through the upper portY of the central aperturearound the valve mechanism, whichl it lubricates and cleanses, and passes down and out throughthe exhaust passages'241, 245

most extreme position, as shown in 13, and reverses the connection so that the high pressure working iluid is now appliedjin` the lower end of the-hydraulic cylinder from thcecnd spacer ring groove down through the groove |59 in the valve, through the third set of port holes |55 from the top, and thence (as shown in Fig. 8) by way ofvpassages 223, 221, 233 and 231 into the lower part oi' the hydraulic cylinder to move the hydraulic piston I9 up. I

In the `above action, IdesireY to point out one important' feature. As-the valve groove |59 is of an axiallength greater than-the spacingV of the ports |55, the initial movement of the valve p does not 'immediately cut AoiI or reserve the hy@- and 24|. 'As `will be understood the inlet port 2|9 of the valve housing is connected through any'suitable conduit orhose having a control valve toa source (not shown) of working iluidf under pressure such-as oil, and the exhaust port' is also similarly connected i'or returning the exhauvsted oil to the source. Y*

l In operation, when my hydraulic operator is coupled toa barrelpump as illustrated, the outerA cylinder, ofthe pump is inserted into the barrel or drum 3 of grease, as shown in Fig. 1, with the lower` end spaced slightly above the 'bottom by the spacing lug 6|.` The high pressure working fluid is then vadmitted into thehydraulic operator where it'is continuously applied in.l thesecond spacer ring from the top fromthe inner endoi the inlet passage 2| 9 as previouslyfdefscribed. Assuming that the hydraulicA piston I9 is up and the valve is positioned, as shown in Fig. `4, the high pressure working fluid passes up through the widegroove |59 in the valve, through the top set of port holes |55, and by way ot passages |63 and |62 into the upper end of the` hydraulic cylinder 2| forcing the piston |.9V downwardly. The working oil previously admitted below the piston I9 is exhausted (see Fig. 8) by way of passages 231, 233, 229, 221 and 223'into the third spacer ring from the top in the valve housing. The exhaust fluid then enters the central orifice |44, in the ported cylinder below the valve, through the third set of port holes and passes down and out through the bottom set of port holes |55, the bottom spacer ring |45 (see Fig. 8) the exhaust port 24|. i Y

As the piston approaches the bottom of its stroke,the upperv piston member |99 strikes the collar 21 secured on theelower end of the valve rod 25. The' downward movement oi the valve rod 25 pulls dow'n on the ring |91 on the upper end of the compression spring in the cam spool and,- when the spring tension is suillcient,

draulicl pressure. Hence hydraulic pressure is available for moving' the piston I9 to its extreme travel," thus "continuing the movement oftthe valve rod` so` as to compress the cam compression spring |85 sufficiently -to overcome all resistance to movement o! thecam Aspool |1| (such as frictionv and the cam `balls |9| held in the cam grooves -by springs |96) and to dforce the camming balls |9| to climbover'dead center of the= separating ridge |95, `beforethe hydraulic pressure is suddenly c'ut oil' in one direction of now.

The piston I9 now moves upwardly and workinguid previouslyfadmitted above the piston is exhausted by way of passages (see Fig. 13) |62, |63, the upper spacer ring and set of ports |55,` into the central "orifice |44 above the valve |51 thence up around the valve 'mechanism in the upper part 'of the `valve vhousing 'andout by way of (see Fig. 8) Vexhaust passages 241, 245 and 24|. As the piston I9 approaches the upper limit of its stroke, the lower'end of the valve rod 25 is engaged by thespacer 29 in the bottom'of the hollow piston rod |5` moving the valve rod up. When the spring in the `cam spool |1| hasl been sufciently compressed, the spring pressed cam balls f |9| being in the upper groove |94, as shown in it overcomes the pressure ofthe springs |96 and snaps'the cam spool to thelower position with a quick snappy action, the cam balls |9| quickly Fig. 13, suddenly spread apart, the cam ridge passes between, and the balls snap together into the lower groove |93. This snaps the cam spool |1| up and due to the slack motion connection moves the valve up with a quick snappy motion at the last moment. This cyclel of operation is repeated by the hydraulic operator as long as suitable working pressure fluid is supplied in the intake port and, through the tubular piston rod I5, power is -transmitted to reciprocate the pump pistons |3 and 9.`

It is apparent that within the scope of the invention, modification, and diiferent "arrangements may be made other than herein disclosed',

. and the present disclosure'is illustrative merely,

lcured on one end of said hydraulic cylinder, a central aperture in said valve housing, said centrai aperture being ot substantially cylindrical conformation and extending in substantial alignment with the axis of said hydyraulic cylin-y der, a ported cylinder of smaller diameter than circumferentially around said ported cylinder and the respective sets of port holes being spaced axialiy at different axial positions in said ported cylinder, spacing rings disposed in the space between the ported cylinder and the side walls of said aperture for supporting said ported cylinder in a concentric spaced relation therein and corresponding in number to the number of sets of port holes in the ported cylinder, said spacing rings being spaced axially along the peripheral outer wall of said ported cylinder at distances or positions coinciding with the axially spaced sets of port holes in the ported cylinder, each spacing ring having a groove or cut out portion provided with ports in conductive connection with all the port holes of an adjacent set in the ported cylinder, a valve slidable in snug iitting relation in said ported cylinder, a groove in the outer peripheral wail of said valve, said groove extending circumferentially around said valve and being of suilicient axial length to simultaneously overlap for conductively interconnecting the port holes oi' two adjacent sets oi port holes in the ported cylinder, iluid conducting passages extending from opposite ends of said hydraulic cylinder into said valve housing and connecting into the conductive grooves defined by two diilerent spacer rings, an inlet port in said valve housing opening into another groove in another one oi the spacer rings for applying a high pressure working iluid therein for working the hydraulic piston, an exhaustport opening from said housing and'connecting .from another one ofthe grooves defined in another spacer ring, said ports being so related that -the valve by moving to either one of two extreme positions connects the inlet port to apply iluid pressure .on either respective side oi' the hydraulic piston while connecting the other side thereof to exhaust, and valve operating means for actuating the valve to either extreme position substantially as the hydraulic piston completes a stroke in either direction.

2. A hydraulic motor comprising the combination dened by claim number 1 and having yieldable gaskets between said spacing rings for sealing between the walls of the central aperture and the ported cylinder. 1

3. A hydraulic'motor having in combination a hydraulic cylinder, a hydraulic piston slidable operatively in said cylinder, a valve housing mounted on one end of said hydraulic cylinder, a central aperture in said valve housing, said central aperture being of substantially cylindrical i conformation and extendingin substantial alignment with the axis of said hydraulic cylinder, a ported cylinder of smaller diameter than said aperture, four sets of port holes opening through the side walls of said ported cylinder, the port holes of each set being spaced circumferentially around said ported cylinder and the respective sets of port holes being spaced axially at different axial positions in said ported cylinder. four spacing rings disposed in the space between the ported cylinder and the side walls of said aperture for supporting said ported cylinder in a concentric spaced relation therein, said spacing rings draulic piston completes a being spaced axially along the peripheral outer wall ot said ported cylinder at distances 0r positions coinciding with the axially spaced sets of port holes in the ported cylinder, each spacing ring having a groove or cut out portion provided with ports in conductive connection with all the port holes of an adjacent set in the ported cylinder, arvalve slidable in snugnttins relation in said ported cylinder, a groove in the outer peripheral wall of said valve, said groove extending circumierentially around said valve and being of su'ilicient axial length to simultaneously overlap for conductively interconnecting the port holes oi' two adjacent sets of port holes in the ported cylinder, iluid conducting passages extending from opposite ends of said hydraulic cylinder into said valve housing and connecting into the conductive grooves dened by two different spacer rings being the top ring and the third from the top, an inlet port in said valve housing opening into the groove in the second spacer ring trom the top for applying a high pressure working iluid therein for working the hydraulic piston, an exhaust port opening from said housing and connecting from the groove dened in the bottom spacer ring and also opening from the space in said central aperture above said spacer rings and valve. said ports being so related that the valve by moving to its uppermost extreme position connects two uppermost sets oi' ports applying iluid pressure in the connected end of the hydraulic cylinder while connecting the other end of the cylinder to exhaust. and the valve by moving to the other extreme position, which is its lowermost position, connects the second and third sets ot port holes applying pressure in the oppodte end of the hydraulic cylinder while opening the upper set oi.' port holes to the space in the central aperture above the valve for ex` haust therethrough to the exhaust port, and valve operating means for actuating the valve to either extreme position substantially as the hyu stroke in either direc- 4.A hydraulic motor comprising the combinanon deaned by claim number s and navingyieidable'gaskets between said spacing rings for sealing between the walls of the central aperture and the ported cylinder.

5. A hydraulic motor having in oombinatiory.

a hydraulic cylinder, a hydraulic piston slidable operatively in said hydraulic cylinder, a valve housing mounted on one end of said hydraulic cylinder, an inlet port in said valve housing for receiving a working iluid under pressure for ac- .tuating said hydraulic piston, an exhaust port in said housing for discharging working fluid from said hydraulic cylinder. fluid conducting passages extending from opposlte'ends ci' said hydraulic cylinder into said valve housing, a valve in said housing movable to either one of two extreme positions, iluid conducting ports and passages so arranged in commotion with said valve that in one position thereof conductive connection is established from said inlet port and from said exto a device to be Operated, a valve rod extending.

from said valve into said hollow rod, cooperative engageable means actuated by said hydraulic piston and the hollow piston rod for reciprocating the valve rod when the hydraulic piston approaches either end of its stroke for throwing the valve to either alternate extreme position for reversing as the piston approaches the end of a stroke in either direction, and snap action means associated with said valve actuating means for moving the valve to either extreme position with a quick snappy action just as the piston has substantially completed its stroke.

6. A snap action valve operating mechanism comprising, a valve having an aperture extending axially therethrough, a valve rod extending slidably through the aperture in the valve, a spring concentrically disposed on an extending end of said valve rod, retaining members spaced apart on said rod for engaging the opposite ends of said spring for holding the spring compressed,

obstruction means on said rod for limiting the axial movement of said retaining members apart from each other, either of said retaining members being movable toward the other for further compressing the spring, a cam spool having an aperture extending axially therethrough., said cam spool being disposed concentrically on said rod over said spring, the ends of the axial aperture in the spool being reduced to engage the retaining members compressing the ends of the spring, means connecting the cam spool operatively with the valve, the outer surfaceN of said cam spool having camming irregularities, and resilientsnapover means engaging said cammingirregularities for moving the cam spool in either direction with a quick snappy action whenit has been moved apredetermined distance in either direction by said rod. n

7. A snap action valve operating mechanism comprising, a valve having an aperture extending axially therethrough, a valve rod extending slida- -bly through the aperture in the valve, a spring concentrically disposed on an extending end of said valve rod, retaining members spaced apart on said rod for engaging the opposite ends of said spring for holding the lspring compressed, obstruction means on said rod for limiting the axial movement of. saidretaining members apart from each other, either of said retaining members being movable toward the other for further compressing the spring, a cam spool having an aperture extending axially therethrough, said cam spool being disposed concentrically on said rod over saidspring, one end of the axial aperture in the spool being-reduced to engage one retaining member compressing one end of the spring, the other end of said aperture beinginternally threaded, a plug threadably disposed in the threaded end of said aperture and having an aperture of reduced diameter for passing the rod freely therethrough while engaging the other retaining member for compressing the other end vof the spring, means connecting the cam spool it has been moved a predetermined distance `in either direction by said rod. 

